A case of Cutis Diffuse Leishmaniasis is studied in respect to its immuno logical aspects. Cell mediated immunity was investigated with a battery of nine intradermal antigens, using disposable 1.0 ml tuberculin syringes, with 25 guage oedles. Also, artificial sensibilization to the DNCB and dosage of the Macrophage Inhibiting Factor (MIF) were carried out. Some of the intradermal tests were positive and the leishmanine reaction was negative showing specific anergy. The G and M immunoglobulines were elevated. Since circulating antibodies have been described in the literatura and our patient had tpe C³ complement at a low level we ponder about its consumption fixed to Ag-Ac complexes, which could explain the episodes of fever and arthralgias. Finally, the view points of different authors are considered in relation to the fact that CDL would be caused by a different species of leishumania, or by immunological defect of the host. Convit's reatons undoubtedly favors th is last hypothesis.